Amyotrophic lateral sclerosis (ALS), commonly known as Lou Gehrig’s disease, is a progressive neurological disorder that affects nerve cells responsible for controlling voluntary muscle movement.
The disease can begin gradually, and its earliest symptoms may be easy to overlook. Importantly, many of the symptoms associated with ALS can also occur with other, much more common medical conditions. Having one of these symptoms does not mean that a person has ALS.
Recognizing persistent or unexplained changes in muscle function can, however, help people know when it is appropriate to seek medical evaluation.
What Is Lou Gehrig’s Disease?
ALS affects motor neurons—the nerve cells that control voluntary muscles. As these neurons become damaged, muscles can gradually become weaker.
Over time, ALS may affect movements involving the arms and legs, speech, swallowing, and eventually breathing.
The progression varies considerably from one person to another. Early symptoms may also differ depending on which muscles are affected first.
What Are the First Symptoms of ALS?
There is no single first symptom that occurs in everyone with ALS. Early signs can include several different types of muscle or movement problems.
1. Muscle Weakness
One of the most common early features is gradually worsening muscle weakness.
A person might notice difficulty with tasks that were previously easy, such as:
- Opening jars
- Turning keys
- Buttoning clothing
- Holding objects
- Climbing stairs
- Walking normally
- Lifting an arm
- Getting up from a chair
The weakness may initially affect one part of the body more than another.
Persistent or progressive weakness should be evaluated by a healthcare professional rather than assumed to be ALS.
2. Muscle Twitching
Some people with ALS experience visible muscle twitching, known medically as fasciculations.
These small, involuntary movements can occur in different parts of the body and may be particularly noticeable when the muscles are relaxed.
However, muscle twitching is very common and usually does not indicate ALS. It can occur with fatigue, stress, caffeine use, exercise, certain medications, and several other conditions.
Twitching becomes more concerning when it occurs alongside persistent, progressive muscle weakness or other neurological changes.
3. Muscle Cramps and Stiffness
Muscle cramps can occur in ALS and may sometimes accompany weakness.
Some people may also develop increased muscle stiffness or tightness, known as spasticity.
Again, cramps and stiffness have many possible causes, so these symptoms alone cannot establish a diagnosis of ALS.
4. Difficulty Walking or Maintaining Balance
When ALS affects muscles in the legs, early symptoms may include changes in walking.
A person might notice:
- Frequent tripping
- Difficulty climbing stairs
- A foot that feels weak or difficult to lift
- Increasing difficulty walking
- Changes in coordination related to muscle weakness
An unexplained or progressive change in walking deserves medical attention, particularly if it continues to worsen.
5. Changes in Speech
ALS can sometimes initially affect the muscles used for speaking.
This may cause speech to become:
- Slower
- Less clear
- Slurred
- Softer than usual
- More difficult to understand
Doctors may refer to this type of speech difficulty as dysarthria.
Sudden speech difficulty is different and can be a medical emergency because it may indicate a stroke. Sudden neurological symptoms should receive immediate medical attention.
6. Difficulty Swallowing
Some people with ALS develop problems controlling the muscles involved in swallowing.
Possible signs include:
- Coughing while eating or drinking
- Choking episodes
- Difficulty swallowing certain foods
- Taking longer to finish meals
- Changes in speech or voice after swallowing
Difficulty swallowing can have many causes. Persistent swallowing problems should be assessed by a healthcare professional because they can increase the risk of choking or aspiration.
7. Changes in Hand Function
When ALS begins in the muscles of the hands or arms, everyday activities may become unexpectedly difficult.
For example, a person may notice trouble:
- Writing
- Using utensils
- Turning a doorknob
- Gripping objects
- Using a phone
- Handling buttons or zippers
The important feature is generally progressive loss of strength or function, rather than occasional clumsiness.
Can ALS Cause Muscle Twitching Without Weakness?
Muscle twitching by itself is usually not enough to suggest ALS.
Fasciculations can occur in healthy people and can be associated with many benign causes.
A medical evaluation becomes more important when twitching is persistent and occurs together with objective or progressive muscle weakness, muscle wasting, speech difficulties, swallowing problems, or other neurological abnormalities.
Does ALS Cause Pain?
ALS is primarily a disease affecting motor neurons, but pain and discomfort can occur, particularly as muscle weakness and stiffness progress.
Pain may also result from muscle cramps, reduced mobility, changes in posture, or prolonged pressure on certain areas of the body.
Pain alone, however, is not considered a specific early warning sign of ALS.
Who Gets ALS?
ALS can affect adults of different ages, although it becomes more common with increasing age.
Both men and women can develop the disease.
Most cases are considered sporadic, meaning they occur without a known family history. A smaller proportion are associated with inherited genetic factors and are described as familial ALS.
Having a family member with ALS does not automatically mean that someone will develop the disease, but people with a significant family history should discuss their individual risk with a healthcare professional or genetic counselor.
How Is ALS Diagnosed?
There is no single test that can independently confirm ALS.
Doctors typically use a combination of:
- Medical history
- Neurological examination
- Assessment of muscle strength and reflexes
- Electromyography (EMG)
- Nerve conduction studies
- Imaging such as MRI when appropriate
- Blood or other laboratory tests to rule out alternative causes
Depending on the situation, additional testing may be necessary.
This is important because several neurological and non-neurological conditions can produce symptoms that resemble ALS.
When Should You See a Doctor?
Make an appointment with a healthcare professional if you experience persistent or progressively worsening muscle weakness, unexplained changes in speech or swallowing, repeated falls, or other neurological symptoms.
You do not need to assume the worst. Many conditions can cause muscle weakness, twitching, cramps, or changes in coordination, and some are treatable.
The purpose of medical evaluation is to determine the actual cause of the symptoms.
Seek Emergency Care for Sudden Neurological Symptoms
If weakness, facial drooping, difficulty speaking, severe dizziness, loss of coordination, or another neurological symptom appears suddenly, seek emergency medical attention.
Sudden neurological